Quatech MPAP-100 user manual Interrupts

Page 28

8 Interrupts

The MPAP-100 will operate using the interrupt level (IRQ) assigned by the PCMCIA system. Interrupts can come from the SCC, the external FIFOs or RS-232 test mode. The interrupt source is selected by bits 4 and 5 of the Configuration Register (see page 41).

When using interrupts with the MPAP-100, the application must have an interrupt service routine (ISR). There are several things that an ISR must do to allow proper system operation:

1.If the external FIFOs are enabled, read the Interrupt Status Register (see page 43) to determine whether the interrupt was caused by a FIFO event or by theSCC.

2.If the TX_FIFO bit is set, at least 512 bytes can be written to the Tx FIFO. If the

RX_FIFO bit is set, at least 512 bytes can be read from the Rx FIFO. I/O block move instructions may be useful. Check the FIFO Status Register (see page 44) after servicing the FIFO(s) to see if further FIFO service is required.

3.If the SCC bit is set, do an SCC software interrupt acknowledge by reading Read Register 2 in channel B of the SCC. The value read can also be used to vector to the appropriate part of the ISR.

4.Service the SCC interrupt by reading the receiver buffer, writing to the transmit buffer, issuing commands to the SCC, etc.

5.Write a Reset Highest Interrupt Under Service (IUS) command to the SCC by writing 0x38 to Write Register 0.

6.Check for other interrupts pending in the SCC by reading Read Register 3. Perform further interrupt servicing if necessary.

7.For applications running under DOS, a nonspecific End of Interrupt must be submitted to the interrupt controller. For Interrupts 2-7 this is done by writing a 0x20 to port 0x20. For Interrupts 10-12, 14 and 15 this is done by writing a 0x20 to port 0x60, then a 0x20 to port 0x20 (due to the interrupt controllers being cascaded). Device drivers running under other operating systems may have varying requirements concerning the End of Interrupt command.

For further information on these subjects or any others involving the SCC contact Zilog for a complete technical manual.

Image 28

Contents MPAP-100 RS-232 PCMCIA SYNCHRONOUS ADAPTER Users Manualfor PCMCIA Card Standard compatible machines QUATECH, INCWARRANTY INFORMATION MPAP-100PRODUCT DESCRIPTION Single Channel PCMCIA RS-232-D Synchronous Communications AdapterCopyright 2001 Quatech, Inc 5.2.1 Tying a configuration to a particular socket 5.3 OS/2 Client Driver Configuration Examples5.4 Monitoring The Status Of PCMCIA Cards Table of ContentsTable of Contents 10.3.1 Using channel A for both transmit and receiveAccessing the SCC while FIFOs are enabled 22.1.4 Older Versions of Card and Socket Services1 Introduction 1.1 System Requirements2 Hardware Installation 3 DOS / Windows 3.x Software Installation 3.1 MPAP-100 Client Driver for DOS 3.1.1 DOS client driver installationDEVICE=drive\path\MPAP1CL.SYS S#,B#,I#,C ... S#,B#,I#,C 3.1.2 Auto Fallback configuration 3.1.3 Hot SwappingPage 3.2 DOS Client Driver examples DEVICE=C\MPAP-100\MPAP1CL.SYSDEVICE=C\MPAP-100\MPAP1CL.SYS b300,c DEVICE=C\MPAP-100\MPAP1CL.SYS s0,b300,i53.3 MPAP-100 Enabler for DOS 3.3.1 DOS Enabler Installation3.3.3 Configuring a card 3.3.2 Hot Swapping is not supportedMPAP1EN S#,B#,I#,W#,C 3.3.4 Releasing a cards configuration MPAP1EN S#,R,W#3.4 DOS Enabler Examples MPAP1EN.EXE s0,b300,i5,cMPAP1EN.EXE s1,b300,i3,wd8 MPAP1EN.EXE s0,r4 Windows 95/98 Installation 4.1 Using the Add New Hardware WizardPage Page 4.2 Viewing Resources with Device Manager 4.3 Configuration Options 5 OS/2 Software Installation 5.2 OS/2 Client Driver Installation5.1 System Requirements DEVICE=drive\path\MPAP100.SYS addr,irq,C ... addr,irq,C5.2.2 Auto Fallback configuration 5.2.3 Hot Swapping5.5 Installing OS/2 PCMCIA Support DEVICE=C\MPAP-100\MPAP100.SYS 300,5Page 6 Using the MPAP-100 with Syncdrive 7 Addressing 8 Interrupts 9 SCC General Information SDLC/HDLC Bit Synchronous CommunicationsByte-oriented Synchronous Communications Asynchronous Communications9.1 Accessing the registers Example 3 Write data into the transmit buffer of channel A Master interrupt control and reset coding, CRC resetInterrupt control, Wait/DMA request control Interrupt vector9.2 Baud Rate Generator Programming 9.3 SCC Data Encoding Methods9.4 Support for SCC Channel B ClockFrequency TimeConst 2 BaudRate ClockMode9.4.1 Receive data and clock signals 9.4.4 Other signals are not used9.4.2 Extra clock support for channel A 9.4.3 Extra handshaking for channel A9.5.1 Register Pointer Bits 9.5 SCC Incompatibility Warnings9.5.2 Software Interrupt Acknowledge 10.2 Accessing the FIFOs 10 FIFO Operation10.1 Enabling and disabling the FIFOs 10.2.1 Transmit FIFO10.3 SCC configuration for FIFO operation 10.2.2 Receive FIFORegister 10.3.2 Using channel B for receive 10.4 FIFO status and control 10.4.1 Interrupt status10.4.2 Resetting the FIFOs 10.5 Accessing the SCC while FIFOs are enabled10.4.3 Reading current FIFO status 10.4.4 Controlling the FIFOsPage 10.7 Receive FIFO timeout 11 Communications Register SWSYNCBit 2 TCKEN --- Transmit Clock Source RCKEN --- Receive Clock SourceBits 1-0 Reserved, always 12 Configuration Register INTS1, INTS0 --- Interrupt Source and Enable BitsFIFOEN --- External data FIFO enable External Data FIFOs Present --- Reserved, alwaysRXSRC --- Receive FIFO DMA Source 13 Interrupt Status Register 14 FIFO Status Register 15 FIFO Control Register 16 Receive Pattern Character Register Bits 7-0 Receive Pattern CharacterThis is17 Receive Pattern Count Register Bits 7-0 Receive Pattern CountBit 6 Reserved, always Bits 5-0 Timeout Interval 18 Receive FIFO Timeout RegisterBit 7 X16MODE --- Clock Mode 19 External Connections 19.1 SYNCA pin 19.2 RING pin19.3 Null-modem cables 20 DTE Interface Signals CIRCUIT AB - SIGNAL GROUNDCIRCUIT BB - RECEIVED DATA CIRCUIT CB - CLEAR TO SENDCIRCUIT CC - DCE READY DATA SET READY CONNECTOR NOTATION DSR CIRCUIT CD - DTE READY DATA TERMINAL READY CONNECTOR NOTATION DTRCIRCUIT CE - RING INDICATOR CONNECTOR NOTATION RING CIRCUIT CF - RECEIVED LINE SIGNAL DETECT CARRIER DETECTCIRCUIT TM - TEST MODE 21 Specifications 22 Software Troubleshooting 22.1.3 Multiple Configuration Attempts22.2 DOS Enabler 22.1 DOS Client Driver 22.1.1 Generic SuperClient Drivers22.2.1 With Card and Socket Services 22.2.2 Socket Numbers22.2.3 Memory range exclusion 22.3 OS/2 Client Driver 22.3.1 Resources Not AvailablePage MPAP-100 Users Manual Revision March P/N